So, the idea that the Armored Sled does what powered armor would do is horribly wrong, sorry Yami. Similarly, there's no reason that we can't utilize cover and concealment both, and it'd be first-rate stupid to trade all hope of concealment in favor of additional cover.
The CEK is an overachieving revision at best and purely wasteful at worst---we don't want shields on the frontline, and we don't want to be digging trenches on the frontline either. And even bothering to provide provision for unarmored Mountain Suits to engage in melee combat with hostile forces is....yeah, it's pretty insanely stupid. Unarmored guys fighting in melee went out of style a thousand years ago or more, quit trying to bring it back.
The Devastator is now kind of funny, but still probably not as useful as a simple field gun would be. Also, we don't have functional armor yet, so you're putting the cart before the horse. First figure out what it can carry, then design something to fit the armor.
LFG-13 Light Field Gun (non-motorized)
The LFG-13 is a direct-fire, 40mm artillery piece. It is built to lie extremely close to the ground, with a small gun shield covering two crewmen sitting or crouching next to the gun. It has a long barrel for its size, giving time for its Gavrillium gunpowder to propel solid shot, Gavrillium incendiary (Gavrillium casing filled with explosives, based off of the M2 grenade), or HE rounds to very high velocities. The barrel alloy is based on the GA1b's, as is the Gavrillium gunpowder, to allow for high rates of fire without melting the gun. Due to the high range granted by Gavrillium, extra time has been spent perfecting the rifling and sights to produce unparalleled accuracy. Two wheels allow for the gun to be dragged by the tail by man or by horse or anything else we've got, while the wheeled Boxes o' Ammo allows plenty of rounds to be dragged with the gun without aid of machinery or animals. A four-man crew can move the gun plus its two boxes of ammunition rapidly, and be set up to fire the weapon in seconds. All the steel used in the design is Caelium steel, further improving its mobility.
I'm not reposting the motorized version, I think that this is probably better. It uses some Caelium to keep the whole assembly lightweight, some Gavrillium for the shells, and chemicals for the barrel, but nothing in large amounts. It should instantly be Cheap and capable of wrecking anything from infantry assaults to power armor to vehicles with up to Medium armor.
...darnit this has become another wall of text. Ah well. I'll post a basic "flying armored boat" capable of transporting troops, kind of like a flying Armored Sled, really.